The present invention relates to an antibody having a therapeutic effect on a tumor. That is, the invention relates to an antibody which binds to B7-H3 to exhibit an antitumor activity. An object of the invention is to provide a pharmaceutical having a therapeutic effect on a tumor. By obtaining an anti-B7-H3 antibody which binds to B7-H3 to exhibit an antitumor activity, a pharmaceutical composition for treating a tumor comprising the antibody and the like is obtained.